Which of the following bacteria is associated with Lyme disease?
- A. Borrelia burgdorferi
- B. Clostridium botulinum
- C. Escherichia coli
- D. Streptococcus pneumoniae
Correct Answer: A
Rationale: The correct answer is A: Borrelia burgdorferi. This bacterium is associated with Lyme disease, a tick-borne illness. Borrelia burgdorferi is transmitted to humans through the bite of infected black-legged ticks. It causes a range of symptoms, including fever, rash, joint pain, and neurological problems.
Summary:
B: Clostridium botulinum is associated with botulism, a serious illness caused by a toxin produced by this bacterium.
C: Escherichia coli is a common bacterium found in the intestines of humans and animals, some strains can cause food poisoning.
D: Streptococcus pneumoniae is a bacterium that can cause pneumonia and other respiratory infections, but not Lyme disease.
You may also like to solve these questions
A fecal smear from a patient with chronic diarrhea revealed cysts with four nuclei. What is the most likely causative agent?
- A. Entamoeba histolytica
- B. Balantidium coli
- C. Giardia lamblia
- D. Trichomonas hominis
Correct Answer: A
Rationale: The correct answer is A: Entamoeba histolytica. This protozoan parasite causes amoebic dysentery and is characterized by cysts with four nuclei in fecal smears. It is commonly associated with chronic diarrhea. Balantidium coli (B) presents with large ciliated trophozoites, not cysts. Giardia lamblia (C) has trophozoites with flagella and causes giardiasis, not cysts with four nuclei. Trichomonas hominis (D) typically has a pear-shaped trophozoite and is not associated with cysts with four nuclei.
The specific prevention (by vaccination) of the disease gas gangrene (caused by Clostridium perfringens) is based on:
- A. Killed whole cell vaccine
- B. Anatoxin
- C. There is no specific prevention by vaccination
- D. Alive attenuated vaccine
Correct Answer: B
Rationale: The correct answer is B: Anatoxin. An anatoxin is a toxin that has been rendered harmless while retaining its ability to stimulate an immune response. Gas gangrene is caused by the toxins produced by Clostridium perfringens, not the bacteria itself. Therefore, vaccination with an anatoxin can trigger the immune system to produce antibodies against the toxin, providing immunity against the disease.
A: Killed whole cell vaccine - Gas gangrene is caused by toxins, not the whole bacterium. This type of vaccine may not be effective in preventing the disease.
C: There is no specific prevention by vaccination - This is incorrect, as vaccination with an anatoxin can prevent gas gangrene.
D: Alive attenuated vaccine - Attenuated vaccines contain live, weakened forms of the pathogen. However, for gas gangrene prevention, targeting the specific toxin with an anatoxin vaccine is more appropriate.
Which bacteria is a common cause of urinary tract infections (UTIs)?
- A. Clostridium tetani
- B. Escherichia coli
- C. Mycobacterium leprae
- D. Bacillus anthracis
Correct Answer: B
Rationale: The correct answer is B: Escherichia coli. E. coli is the most common cause of UTIs due to its ability to colonize the urinary tract. It possesses adhesive factors that enable it to attach to the bladder and cause infection. Clostridium tetani causes tetanus, Mycobacterium leprae causes leprosy, and Bacillus anthracis causes anthrax, none of which are typically associated with UTIs. E. coli's prevalence in the gut and its pathogenic mechanisms make it the leading cause of UTIs.
Which of the following bacterial structures has endotoxic activity?
- A. Lipopolysaccharides
- B. Lipoproteins of Braun
- C. Protein A
- D. None
Correct Answer: A
Rationale: The correct answer is A: Lipopolysaccharides. Lipopolysaccharides (LPS) are major components of the outer membrane of Gram-negative bacteria and are known to have endotoxic activity. LPS can trigger a strong immune response leading to inflammation and septic shock.
Choice B, Lipoproteins of Braun, are not known to have endotoxic activity. Choice C, Protein A, is a surface protein found in Staphylococcus aureus and is not associated with endotoxic activity. Choice D, None, is incorrect as LPS is indeed a bacterial structure with endotoxic activity.
Two weeks after hemotransfusion a patient developed fever. What protozoal disease can be suspected?
- A. Malaria
- B. Toxoplasmosis
- C. Leishmaniasis
- D. Amebiasis
Correct Answer: A
Rationale: The correct answer is A: Malaria. Two weeks after hemotransfusion, the onset of fever indicates a possible bloodborne infection. Malaria is a protozoal disease transmitted through infected blood, causing symptoms like fever. Toxoplasmosis, Leishmaniasis, and Amebiasis are not typically associated with fever following hemotransfusion. Malaria fits the timeline and mode of transmission in this scenario.